Extrusion Profile for Transport and Drive Belts
The invention relates to an extrusion profile of a thermoplastic material for transport and drive belts according to the preamble of claim 1, and to a method for producing said extrusion profile.
A large number of extruded belts made from a thermoplastic material, especially on a polyurethane and polyester basis, are used in drive and transport technology. For their production, a profile (profile material) is extruded as yard ware and is, in most cases, welded in a suitable length to form an infinite belt. Depending on the intended purpose, the belts are constructed as round belts, V-belts, flat belts or with another profile cross-section.
A known way of increasing the tensile strength and tear resistance of such belts is by embedding a core as a tension-bearing element into the extrusion profile made from the thermoplastic material during the extrusion process. This tension-bearing element consists of a strand of reinforcement fibers, for example, aramide fibers, glass fibers or carbon fibers, or a nylon or wire rope.
With these known tension-reinforced belts, problems occur when the extrusion profile is welded into infinite belts. The tension-bearing core impedes the thermoplastic welding of the plastic. The tension-bearing core is therefore commonly removed before the welding from the ends of the extrusion profile that will be welded to each other, so that only the thermoplastic material abuts at the welding point and is welded. The removal of the tension-bearing core is a time-consuming work step. But the removal of the tension-bearing core at the welding point particularly results in an unreinforced weak point of the belt that has a lower tearing and strain resistance. The known belts therefore have a tendency to tear at the welding seam.
The invention has the object of making available an extrusion profile for transport and drive belts with high tensile strength and tear resistance that can be welded into infinite belts without being weakened.
This object is realized according to the invention by an extrusion profile of thermoplastic material for transport and drive belts characterized in that reinforcement fibers with a content of approximately 0.5 to 40 percent by weight are mixed with the plastic of the extrusion profile.
A method for producing the extrusion profile is characterized in that during the extrusion of the extrusion profile, reinforcement fibers with a content of approximately 0.5 to 40 percent by weight are mixed with the plastic.